Concavity and Initialization for Unsupervised Dependency Parsing Kevin Gimpel author Noah A Smith author 2012-06 text Proceedings of the 2012 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies Eric Fosler-Lussier editor Ellen Riloff editor Srinivas Bangalore editor Association for Computational Linguistics Montréal, Canada conference publication gimpel-smith-2012-concavity https://aclanthology.org/N12-1069/ 2012-06 577 581